You might be an in-house counsel, but if you want to get paid a contingency fee by your employer, just like outside attorneys, you need to get it in writing: otherwise it's unenforceable.
Justice Rubin isn't entirely with the breadth of the majority opinion, and might allow some in-house counsel to enforce oral contingency fee agreements in certain settings. But at least after today's opinion, in-house counsel are forewarned:
Get it in writing.